This invention relates generally to techniques for concentrating or directing the output from lighting fixtures and modifying the fixtures"" appearance in the off and/or the on state.
Lighting fixtures, e.g. the recessed xe2x80x9ccan lightsxe2x80x9d used in architectural lighting, have traditionally used a variety of techniques to efficiently direct or otherwise manipulate their light output. For example, the fixtures may be designed to be recessed into a wall or ceiling, may incorporate reflectors or lenses or may incorporate baffles or shields.
However, manipulation of the light output or increase efficiency often comes at the price of a less pleasing appearance when the lighting fixture is turned off or on. Recessed xe2x80x9ccan lightsxe2x80x9d for example, look like holes in the ceiling plane when they are off; xe2x80x9cwall washerxe2x80x9d fixtures, i.e. fixtures set into a ceiling and configured to throw light onto an adjacent wall, often project below the surface of the ceiling and are often of low efficiency; reflectors used to direct light downwards can create glare to a viewer""s eye.
The problem of unattractive lighting fixtures has become worse with the advent of high-efficiency, compact fluorescent bulbs replacing simple incandescent bulbs in many lighting fixtures. These compact fluorescent bulbs, with their large, twisted glass tubes, are unpleasing to the eyes, and since they are much less of a point source than incandescent bulbs, do not lend themselves to simple, efficient reflector design.
At present, the practical solutions to the above problems are limited. For example, certain grids of vanes have been placed in front of the light source to shield a viewer""s eyes from glare coming from the bulb or its reflector or to make a light look like less of a hole in the ceiling. Sophisticated and precisely shaped reflectors can be incorporated into a compact fluorescent lamp""s fixture to try to direct light from the bulb efficiently in the desired pattern. PAR-type lamps can be mounted at an angle inside a recessed fixture to wash a wall with light without a bulb or fixture hanging below the plane of the ceiling.
Those approaches each suffer from significant disadvantages. Current grids of shielding vanes can reduce the efficiency or restrict the angle of illumination of a fixture. Sophisticated and precisely shaped reflectors are expensive to manufacture. PAR-type lamps are substantially more expensive than standard-type bulbs.
Accordingly, it would be highly desirable to have other techniques to manage the light output from a lighting fixture as well as provide an aesthetically pleasing appearance when the fixture is in the either on or off state.
The invention provides a lighting structure that comprises a plurality of tubular elements at least partially embedded into an at least substantially transparent lens structure of a lighting fixture. The lighting fixture is typically a device employed for interior use, particularly interior commercial or residential buildings. The lens structure may be of any of a number of materials that are employed to disperse or enhance light produced by and/or shield the light producing element(s) of the lighting fixture. For example, the lens structure may be a standard lens element, or may contain a plurality of lens-like or other light modifying elements positioned at the front of a lighting fixture. The lens or lens-like elements direct light coming from the fixture""s light source and reflector outward through the tubular elements.
By partially embedding the array or plurality of tubular elements into the transparent lens structure, the fixture can appear as if it is substantially a part of the surrounding surface when the lighting fixture is turned off (i.e. light bulb or other light producing elements not emitting light). Nevertheless, when the light is turned on (i.e. light bulb or other light producing elements emitting light) light coming from the fixture can still be directed or modified in an appropriate manner, e.g. without detrimental light output reductions), and without the need of an expensive, sophisticated reflector or any necessity of the fixture extending beyond the surrounding surface as has been utilized in certain prior attempts to mask architectural lighting fixtures. Still further, while the light fixture is turned on, an unsightly bulb or glaring reflector can be masked from a viewer""s eye as a result of the partially embedded tubular elements.
The invention also includes methods for manufacturing lighting devices of the invention. Those methods comprise in general steps of heating a lens material to at least its glass transition temperature; at least partially embedding an array of tubular elements into the heated lens material; and cooling the lens material with tubular elements embedded therein whereby lens elements form around and/or between the tubular elements.
Other aspects of the invention are disclosed infra.